People are generally aware of the most common causes of hallucinations, like schizophrenia and a really high fever. But lesser known are the more rare causes; here are six you probably haven't heard about.

Greek health authorities urged the public to take health precautions on Friday after a suspected cholera case was discovered on Kos island, a tourist destination and entry point for migrants from the Middle East and Asia.

A group of lawyers representing Haitian cholera victims threatened legal action against the UN on Wednesday, claiming the peace organization failed to take responsibility for a deadly cholera outbreak.